Field of the Invention
The present invention relates to an image forming apparatus and an image forming method.
Description of the Related Art
Electrophotographic image forming apparatuses are widely used, in which a toner image formed on a photoreceptor is transferred to a recording medium such as a sheet, and the recording medium having the toner image transferred thereon is heated and pressurized in a high-temperature fixing section, whereby the toner image is fixed on the recording medium. Electrophotographic image forming apparatuses are applied, for example, to copy machines, printer devices, facsimile machines, printing machines, and multifunction devices.
In the case where the recording medium is a sheet rolled into a roll form (hereinafter, referred to as a “roll sheet”), or a continuous-form paper sheet, the sheet is set in the fixing section even during standby (not printing) when printing is not performed. During printing operations, the sheet is conveyed in a state where the temperature of the fixing section is increased to fix the toner image onto the sheet. On the other hand, during standby, the sheet is stopped, and hence, may deform or discolor due to the temperature of the fixing section. The sheet deformed or discolored is treated as a so-called waste sheet (spoiled sheet).
Patent Literature 1 discloses a technique that prevents the sheet from deforming or discoloring due to the temperature of the fixing section. With the conventional technique described in Patent Literature 1, a conveying roller pair is driven or stopped in a sheet conveying direction at a specified interval during standby in which the sheet is stopped, to remove the slack of the sheet, thereby preventing the sheet from deforming or discoloring due to contact of the sheet with a hot roll.